1. Field of the Invention
The present invention relates to an incliner chair, and more particularly to the carriage mechanism mounted therein which operates to move the seat, backrest, legrest and footrest when the incliner chair is converted from its upright state to its reclined state, and vice versa.
2. The Prior Art
An incliner chair, otherwise known as a "one-way" recliner chair, is a chair which employs a shiftable carriage mechanism that mounts the seat and backrest such that they will retain the same position and orientation relative to one another when the chair is converted between its upright state and its reclined state, i.e., so that the seat and backrest effectively form a unit. The frame of the chair in which the shiftable carriage mechanism is mounted remains stationary on the flooring surface on which it is positioned.
The early incliner chairs included no positive locking mechanisms or extension springs because they were weight or "gravity" operated. Later developed incliner chairs, which often contained overstuffed seats and back cushions, as well as fabrics which would not easily slide over each other, incorporated a main extension spring to help move the seat and backrest when the chair was converted to its reclined state (sometimes the occupant of the chair would not be heavy enough to cause the chair to the chair the main extension spring would be stretched to its maximum extent and apply a large force tending to convert the chair to its reclined state, thus necessitating the use of a locking mechanism to prevent inadvertent reclining of the chair. These locking mechanisms included an auxiliary spring in order to bias them into a locked condition. However, the use of both a main extension spring and an auxiliary spring for the locking mechanism results in a carriage mechanism which is complex and costly to manufacture.
In my U.S. Pat. No. 4,895,411, I have described a shiftable carriage mechanism for an incliner chair formed of left and right support assemblies which are interconnected by a torque tube and which do not utilize a main extension spring. Instead, each support assembly includes a toggle drive subassembly that includes two rotatable toggle links and a drive spring which biases the toggle links into a locked state when the support assembly is in a retracted condition (this corresponds to the shiftable carriage mechanism as a whole being in a retracted state and the incliner chair being in an upright condition), and when the toggle links are rotated to an unlocked state by an occupant in the chair, to assist the weight of an occupant in the chair to extend the support assembly (and thus the carriage mechanism as a whole) and cause the incliner chair to convert into its reclined state. I have now developed a modified version of such a shiftable carriage mechanism wherein the toggle drive subassemblies of the support assemblies provide improved action in assisting the weight of an occupant in moving the mounting rail downwardly towards the base member so that the support assemblies will extend and in causing the toggle links to rotate into a locked state as the support assemblies are retracted by the occupant in the chair.